Pi2 GPIO Pin and Filament Sensor

I'm using a Pi2 with Ocotprint 1.3.10 and more than happy with that version. I connect to it with hardwired Ethernet since at times WiFi is iffy, a Pi camera so I can watch it remotely and an AM2302 Temperature/RH sensor on GPIO4.

I bought an SPDT filament sensor and see that there are a few inputs available. I'm wondering if there is a standard pin used for filament sensors. I will be adding outputs for enclosure lighting and perhaps even a heater but that's in the future.

So is there one specific GPIO pin everyone uses for the filament out sensor? Or just pick one?

You pick one. It's always good to write a readme or other log to remind yourself which cable does what the next time you add something there.

Please, update OctoPrint. 1.3.10 is over 2 1/2 years old now.

My last upgrade of Octoprint resulted in a major crash because the OS was also to old. At that time I was a financially contributing monthly member to patreon. Because Octoprint wasn't smart enough to check whether it had been tested with the older OS I was told it was my fault for not always running the latest version of everything.

So I stopped paying shortly after that. And decided that like the WIN-XP system, which runs my CNC router with MACH3 perfectly, there was no reason to upgrade what wasn't broken. It's still not broken so like my 1935 Delta 14" band saw, I see no reason to upgrade.

But thanks for the suggestion.

Thank you. No standard then. I'll pick one.